I'm an only child. I am 60 yrs old & in the last yr I lost my 36 yr old son & 9 yrs ago my husband. My mom is bipolar & has moderate dementia. I drive 1 hr one way every other week & more when needed to ck on her. She never has offered a cent or a thing else. Last week I took three bags full of cookies & candy hoping it would last a while. This was on Tuesday, & today is Sunday. All she likes is sweets. I do make sure other things are in the house. She must eat night & day. I have 0 help with her because she has been so mean. She is on three powerful meds for bipolar & looks likes a picture of health her memory is just going.
My parents are in fairly good health for being in their 90's, no major issues with memory.... any time I get my Mom's weekly grocery list she has checked off Little Debbie's Fudge Rounds; Little Debbie's Zeba; Entenmann's chocolate chip muffins [buy one get one free]; Pepperidge Farm soft cookies; Tasty Cake chocolate cupcakes; store made apple pie; fudge ripple ice cream; etc. I honestly believe my parents have *dessert* after every meal :P
As for the meds changing one's taste buds, last week I was on some powerful antibiotics and I was surprised how bland my favorite frozen mac & cheese tasted, had to throw it out. Now that I am off said antibiotics, stuff is starting to taste normal again :)
I'm sorry you've lost so many of your close family members, that can't be easy. I'm sure you're doing the best you can do, but your mother may need more than that as time goes by. Is there someone else who can check up on her in between your visits? Be sure you or someone else gets durable and medical powers of attorney before too much time passes. She will need more and more help making good choices as time goes by.
However, her diet will suffer and she will become vitamin deficient and she will gain weight if all she eats is sweets. She will eat whatever you bring as soon as you bring it.